Underground water mains are typically buried eight feet below the surface of the ground in order to make certain they are located below the frost line of the soil. These mains and service laterals extending from the water main to residential areas or businesses are continuously breaking or having pools formed therein as a result of age, earth subsidence or the effects of severe weather, particularly cold weather. Such leaks are often noticed when leaking water runs along the main or lateral, and then flows upwardly to reach the ground surface.
In order to identify the exact location of the leak along the water main, the following procedure is generally followed. A truck-mounted drill rig is used to break through the pavement or upper surface above the water main, and drill a short distance into the earth. It is not possible for the truck-mounted rig to drill all the way to the water main due to the likelihood that the drill would strike and damage the water main. Thereafter, a long T-shaped rod, known as a feeler rod, is pushed or driven into the ground by hand and into surface contact with the water main. An electric or mechanical listening device, such as an earpiece or a headphone, is attached to the top of the rod to detect the hissing sound of rushing, leaking water transmitted through the metal water main and metal rod. The same procedure is followed in a second hole and subsequent holes to determine whether such holes have been drilled in a location away from (fainter water rushing sounds) or toward (stronger water rushing sounds) the site of the leak. By drilling a series of holes and driving a number of feeler rods, the exact location of the leak may be determined. Once the leak is found, the ground is carefully excavated at that point to expose the water main and the leak is repaired.
The use of the standard T-shaped feeler rod is extremely arduous due to the pushing downward or pulling downward exertions necessary to move the rod through hard ground, clay and rock into contact with the water main. Severe cold weather adds significant difficulty in inserting the rod into the earth. In typical fashion, at least one worker, and often two, push the rod incrementally into the ground applying all their weight or using a sledgehammer to advance the rod into the ground. Then, the rod is pulled upwardly before being driven downwardly again for a short distance. Because the length of these rods is typically eight to ten feet, it sometimes can take an hour or so before the rod approaches the leak. This method of repeatedly pushing and pulling the rod can cause bodily injuries with terrible strain to the back, arms, shoulders and groin area of the workers performing the leak detecting task.
Accordingly, it is desirable to provide a manually operated leak detection device which is more efficient and safer than the constructions of the prior art. It is also desirable to provide a feeler rod which is continuously driven into the ground adjacent a water main without the need for retracting the rod or using a separate driving tool. It is further desirable to provide a leak detection device which is economically produced and simple to operate.